The invention relates to a device for attaching seal elements in a recess. The invention also relates to a method for attaching seal elements in a recess using a device as well as a method for producing a corresponding device.
Such seal elements or systems are used particularly for so-called gap-maintaining systems in compressor and turbine components of flow machines. Such sealing systems thereby have the task of keeping to a minimum a seal gap between a rotating component, e.g., of a blade system, and a stationary component, e.g., a housing, of the flow machine, and thereby ensuring stable operating behavior while maintaining a high degree of efficiency. The mentioned sealing systems may involve so-called brush seals or labyrinth seals. In doing so, for example, for attaching mounting plates for brush seals, one generally requires recesses or mounting grooves in the relevant component with an undercut. The housing panels used are mortised into these mounting grooves with an undercut and secured by means of a corresponding deformation of the housing panels. To attach labyrinth seals in U-shaped mounting grooves, one generally uses mortise wires. However, a disadvantage of the known devices and methods for attaching seal elements in a recess is that these are designed very elaborately and are therefore time-intensive to install. Also, additional elements such as the mentioned mortise wires are required.
A device is known from DE 10 2013 205 922 A1 for attaching seal elements in a recess that enables one to simply and rapidly install the seal elements. In addition, the described fixing bodies allow for secure installation and good retention due to a force-fit with a brush seal housing by means of self-retention. However, placement procedures and component vibrations may result in an undesired detaching of the fixing body.
The object of the present invention is therefore to create a device and a method for attaching seal elements in a recess, which ensure additional protection against the detaching of the fixing body. An additional object is to produce a generic device in a geometrically accurate and cost-effective manner.
Advantageous embodiments of the device shall be considered as advantageous embodiments of the attachment method according to the invention and vice versa.
A device according to the invention for attaching seal elements in a recess has at least one seal carrier element comprising at least one seal element. At least one fixing body is thereby arranged between the seal carrier element and a clamping body assigned to the sealing carrier element, where the fixing body is connected to the seal carrier element and the clamping body in an integral manner through bar-like connections that are detachable when subjected to a force. There is also designed on the fixing body at least one plastic deformable structure. By means of the design according to the invention of the device for attaching seal elements, on the one hand simplified and faster installation of the seal elements is made possible by the fact that elaborate grooves with an undercut as well as additional attachment elements can be omitted since the fixing body, in a mortised state, ensures a force-fit between the device according to the invention and the recess or the side walls of the recess. Secondly, the plastic deformable structure assures an additional form-fit between the fixing body and the device according to the invention and the recess or the side walls of the recess. This results in an additional safeguard against loosening of the fixing body during placement procedures and when the component vibrates. In an advantageous design of the of the device according to the invention, the fixing body is designed in such a manner that when the connection disengages between the fixing body and seal carrier element on the one hand and between the clamping body and the fixing body on the other, a force-fit results between the fixing body, the seal carrier element, the clamping body, and side walls of the recess as does a form-fit at least partially between the plastic deformable structure and the seal carrier element and/or the clamping body. In this way, a more secure attachment of the device according to the invention is ensured in the installation groove or the recess by a force- and form-fit. In addition, the attachment of the device according to the invention is possible by means of a simple mortising of the fixing body and the resulting force- and form-fit. The mentioned recess may be an installation groove designed in a flow machine.
In additional designs of the device according to the invention, the plastic deformable structure is designed as at least a bar- or pin-like projection on an end, of the fixing body, pointing to the recess. Other shapes are also possible. It is important in the design of the structure that it is sized in such a manner that a plastic deformation of the material of the structure or the structure itself is possible when subjected to a force. The fixing body and its plastic deformable structure may thereby consist of a nickel-based alloy for example. Furthermore, there is the possibility that the plastic deformable structure can be inserted in at least one recess designed in the seal carrier element and/or the clamping body, under at least a partial form-fit. The design or the shape of the recess may thereby at least correspond partially to the shape of the bar- or pin-like projection. These design possibilities of the device according to the invention result in secure connections between the fixing body and the seal carrier element and/or the clamping body. However, it is also possible that the shape of the structure is designed for a predetermined expansion and direction of the form-fit. In this way, the structure can be guided in a direction- and target-true manner in a corresponding recess in the seal carrier element and/or the clamping body. The location and position of the deformed structure can thus be determined and can be easily adapted to the existing structural circumstances. In addition, the structure can be designed in a one-piece manner with the fixing body. In this way, the structure with the fixing body can be produced in a particularly inexpensive manner. In particular, the one-piece or integral production of the fixing body takes place by means of an additive or generative production process.
In additional embodiments of the device according to the invention, the seal carrier element can be designed as a housing to accommodate the seal element. The seal element can thereby be designed as a brush seal. Furthermore, it is possible that the seal carrier element is designed as a base element of the seal element, where the seal element is a labyrinth seal with corresponding labyrinth fins.
In an additional advantageous embodiment of the device according to the invention, the bar-like connections are designed in such a manner that they each protrude from the seal carrier element and the corresponding opposite clamping body, while forming an angle pointing in the direction of the recess or installation groove. After mortising and detaching the fixing body from the bar-like connections to achieve the aforementioned force- and form-fit, the diagonally placed connection bars prevent a backward sliding of the fixing body by means of the resulting mechanical clamping due to their arrangement and design. In turn and as a result, secure attachment of the seal elements in the recess is assured.
In additional advantageous embodiments of the device according to the invention, a space is designed between the seal carrier element and the opposing clamping body for accommodating the fixing body with the deformable structure tapering toward the recess. By mortising a correspondingly shaped fixing body, the seal carrier element and the clamping body are moved away from each other in different directions and correspondingly fixed in the recess. A clearance can thereby be designed between a fixing body end pointing toward the recess and a bottom of the recess. The distance between the end of the fixing body and the bottom of the recess may be predefined to define the magnitude of the force- and form-fit between the individual elements of the device according to the invention.
In additional advantageous embodiments of the device according to the invention, the fixing body is designed with the deformable structure generally tapering toward the recess. The fixing body can thereby be designed in a wedge- or frustoconical-shaped manner. Interacting with the space formed between the seal carrier element and the opposing clamping body, this shape of the fixing body results in a secure force- and form-fit between the mentioned elements after a detaching of the fixing body from the bar-like connections and a mortising toward the recess. However, other shapes are also conceivable for the fixing body. The shape of the fixing body must thereby be adapted in each case to the space formed between the seal carrier element and the opposing clamping body. It is thereby important that after a disengagement of the connection between the fixing body and the seal carrier element or the clamping body, there results a force- and form-fit between the fixing body, the seal carrier element, the clamping body and the side walls of the recess.
In additional advantageous embodiments of the device according to the invention, the fixing body with the plastic deformable structure, the seal carrier element, the clamping body, as well as the bar-like connections are designed in a one-piece manner. In particular, the one-piece or integral production of the device according to the invention occurs by means of a generative production process. In addition, it is possible that the fixing body, the seal carrier element, the clamping body, the bar-like connections as well as the seal element designed as a labyrinth seal are also designed in a one-piece manner. Here, too, the integral production of the device can occur by means of a generative production process.
The invention also relates to a method for attaching seal elements in a recess using a device as described previously, where an embodiment of the method comprises the following steps:                a) introducing the device into the recess;        b) applying a force towards the recess on the fixing body in such a manner that a disengagement of the connection between the fixing body and the seal carrier element on the one hand and between the clamping body and the fixing body on the other is effected; and        c) continuing to apply force on the fixing body until on the one hand a force-fit results between the fixing body, the seal carrier element, the clamping body, and side walls of the recess and on the other, at least partially a form-fit between the plastic deformable structure and the seal carrier element and/or the clamping body results.        
This method ensures a simple and rapid installation of the seal elements in the corresponding recess. Advantageously, additional attachment elements or a special and elaborate design of the recess can be avoided. In addition, the fixing element is protected against disengaging from the connection. The recess may be an installation groove designed in a flow machine.
The invention also relates to a method for producing a device according to the invention as described precedingly. The device according to the invention is thereby produced by means of an additive or generative production process. In this way, the generative production process may be a selective laser melting or a selective laser sintering process. Other additive or generative production processes are also conceivable. By using generative production processes, a geometrically accurate and cost-effective production of the device, according to the invention, for attaching seal elements is possible.